Copyright 2020 Robert Clark
In the blog post, "About the Lancet paper on hydroxychloroquine and COVID-19", I discussed a letter I sent to the authors of the recent Lancet paper:
Prof Mandeep R Mehra, MD Sapan S Desai, MD Prof Frank Ruschitzka, MD Amit N Patel, MD
Published: May 22, 2020 DOI:https://doi.org/10.1016/S0140-6736(20)31180-6
The issue I had was with the higher number of patients placed on ventilators among the HCQ group compared to the non-HCQ, over twice as many. COVID-19 patients placed on ventilators have poor outcomes. In New York for example, only 20% of them survive it. This would skew the mortality numbers for the HCQ group towards higher mortality.
So the question then was this: was the higher number of intubated patients in the HCQ group seen in this study because of the HCQ or was it because even after the authors applied methods to compensate for HCQ being given more to the sicker patients, this bias against HCQ still remained in the data?
I'm inclined to believe the latter because while HCQ had been connected to heart problems it was not known to cause breathing problems.
If this is the case then how the authors conducted their statistical adjustments to the data becomes extremely important. I advised the authors to release their data and describe their procedures for how they compensated for HCQ being prescribed to the more sicker patients to begin with.
The authors releasing their data and procedures becomes even more important because of this recent news report:
Questions raised over hydroxychloroquine study which caused WHO to halt trials for Covid-19.
The company that provided the data for the Lancet paper has been accused of falsifying data and Australia has denied ever supplying them with the information they claimed comes from Australian hospitals.
This company, Surgisphere, has refused to hand over their data. In view of the importance of this paper with randomized, controlled trials that could have finally determined the validity of HCQ’s effectiveness being cancelled, the authors should be required to either hand over their data or withdraw their paper.
Because of the controversy and doubt about how the data in such studies that are non-randomized are adjusted to mimic randomized studies, I recommend also the simplified approach I discussed in the prior post mentioned above. It's advantages are its transparency and simplicity. Everyone can see how the numbers are being developed at every step of the process, and anyone with just a hand-calculator can do the calculation themselves, not needing advanced statistical packages to do it.
Letter to the authors of the Lancet paper: